The invention relates to an assembly for temperature control of a fountain (dampening) fluid and/or selected rolls of a printing press. The invention thus concerns in general the field of offset printing.
In a know assembly (EP-A-0 602 312) each of circulating systems for a fountain fluid and for a cooling fluid for supplying a roll cooling device is configured as an open-circuit system, with each circulating system being assigned a reservoir, serving as a buffer storage for the respective fluids of the systems. In this known assembly the reservoir connected to the open-circuit system for circulating the cooling fluid is necessary, since a refrigeration mechanism supplying a heat exchanger mechanism of the circulating systems with refrigerant is designed for a maximum capacity necessary. This means that in an offset printing shop having no cooling of the fountain fluid, the heat exchanger mechanism for the cooling fluid circulating system receives a maximum supply of refrigeration energy which could result in the cooling fluid being excessively cooled, if--as is the case in a closed-circuit system--an amount of cooling fluid available is not sufficient to absorb excess refrigeration energy. In other words, in the known temperature control assembly the reservoir intercepts part of the excess refrigeration energy. Attempting to eliminate the reservoir would necessitate having to repeatedly switch ON/OFF compressor designed for maximum refrigerating capacity to restrict its refrigeration output. This is practically impossible to implement for the short switching cycles which would then be required, since compressors need a certain minimum continuous running time, otherwise there would be a risk of damage with early failure of the compressor. A further drawback of the known assembly is that it has an increased energy demand, since the refrigeration mechanism always needs to be operated at full power, irrespective of a refrigeration output actually provided in each phase of operation.
There is thus a need for an assembly of the kind described above which is improved with regard to at least one of: "system complexity", "energy consumption" or "operating behavior".